package thread;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

/**
 * 线程池
 * 线程池是线程的管理机制,主要解决两个问题:
 * 1.控制线程数量
 * 2.重复使用线程
 */
public class threadPoolDemo {
    public static void main(String[] args) {
        //1.创建一个容量为2的线程池
        ExecutorService threadPool = Executors.newFixedThreadPool(5);
        //2.指派任务
        for (int i = 0; i < 2; i++) {
            Runnable r = new Runnable() {
                @Override
                public void run() {
                    Thread t = Thread.currentThread();
                    System.out.println(t.getName()+"正在执行任务");
                    try {
                        Thread.sleep(5000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    for (int j = 0; j < 10; j++) {
                        System.out.println(t.getName()+"任务执行完毕!");
                    }
                }
            };
            //3.指派任务给线程池
            threadPool.execute(r);
            System.out.println("指派了一个任务给线程池");
        }
        //线程池的关闭
//        threadPool.shutdown();//任务执行完后关闭
        threadPool.shutdownNow();//正在运行的任务完毕后再关闭
        System.out.println("线程池关闭了");
    }
}
